•Typecasting. When scouts go to bed at night, Barkley is the prototype pocket passer they see in their dreams, across the board: He showed up at USC in 2009 as the No. 1 quarterback recruit in America, the latest and most celebrated product of the golden pipeline from nearby Mater Dei High and, within a few months of stepping on campus, the first true freshman in school history to start his first game. Before he even left high school, Barkley had already been on mission trips to build homes for the poor in Mexico, volunteered at an orphanage in South Africa and led a drive to raise money for families of Marines. In terms of advance hype, opportunity at a traditional powerhouse and squeaky-clean charisma, he's the West Coast equivalent of Tim Tebow — except that, in Barkley's case, the NFL scouts are totally enamoredwithhispotential, too.

The fact that he hasn't broken through on anything remotely approaching a Tebow-esque scale is a testament to just how high the bar is for a golden-boy quarterback at USC. Barkley's won 17 games as a starter in two seasons, but also lost as many (7) as predecessors Matt Leinart, John David Booty and Mark Sanchez lost between them from 2003-08. As a freshman, he presided over a dramatic fourth quarter comeback at Ohio State in his second game, but also over two of the worst beatings in school history against Oregon and Stanford. As a sophomore, he finished third in the Pac-10 in passing yards, touchdowns and efficiency, but averaged fewer yards per game than any Trojan passer in a decade, with fewer TDs and a lower rating than any Trojan passer in that span except Booty in 2007. As a junior, Barkley will be the undisputed leader of a lineup uncharacteristically lacking in star power, and may be embarking on his last chance to leave a legacy that transcends the fall of the Trojan empire.

•At his best... On paper, the offense significantly improved last year compared to 2009, and Barkley continued to show flashes of the pocket presence, downfield arm strength and knack for fitting the ball into tight windows that made him such a scout favorite in the first place. He also established a good rapport with true freshman burner Robert Woods, the team's leading receiver, and left no doubt that the offense is built primarily around his right arm.

Most of the goodwill he carries out of 2010 was earned over the first half of the season. Through the first seven games, Barkley passed for multiple scores in six of them, with 20 touchdowns to four interceptions and a seemingly firm grip on Lane Kiffin's new offense. USC rolled to a 4-0 September, and while the defense went to sleep in last-second losses to Washington and Stanford in early October, the offense put the pedal down for 30-plus points and nearly 500 yards of total offense in both. Personally, Barkley dueled Andrew Luck to a draw with went 390 yards and three touchdowns in a losing effort against the Cardinal, and bounced back the following week to bury Cal beneath five touchdown passes in the first half alone en route to a 48-14 massacre. Going into the Oct. 23 bye week, USC was 5-2, averaging 494 yards and 37 points per game — both top-15 numbers nationally — and Barkley was the highest-rated passer in the Pac-10.

•At his worst... After the by week, things started to fall apart. Barkley turned in arguably his worst game on Oct. 30, serving up two interceptions and botching a shotgun snap (with some help from Kiffin) that helped turned the tide in an eventual 53-32 beatdown at the hands of Oregon on the season's biggest stage. Beginning with the loss to the Ducks, his last five starts included just six touchdowns to eight interceptions — twice as many as he threw over the first seven games — and zero 300-yard efforts. From Oct. 2 to Nov. 27, USC dropped five of eight games, with two of the three wins coming by one point (34-33 over Arizona State) and three points (24-21 over Arizona), respectively. Well before he was knocked out of the Nov. 20 loss at Oregon State with an injured ankle, Barkley had already thrown a pick-six and was battling through the most nightmarish first half of his career in a humiliating, 36-7 flop.

Even with a relatively consistent running game keeping defenses honest, the occasional Favre-like tendency to strong-arm balls into coverage led to another season of double-digit picks, and contributed to the diminishing returns down the stretch. Barkley didn't play at all against Notre Dame, another disappointing loss in a driving rainstorm, and returned only to serve up two more picks in an ugly finale at UCLA. That win left the offense averaging a full 60 yards and six points less per game for the season than it was averaging at the bye week, and even within the Pac-10, Barkley finished squarely in the middle of the pack by every significant statistical measure.

•What to expect in the fall. There was some progress in the first season under Kiffin's watch, even if it wound up being of the "two steps forward, one step back" variety. But Year Three is where the rubber meets the road: For other massively hyped pocket slingers like Jimmy Clausen, Mark Sanchez, Matt Stafford, Matt Ryan and Brady Quinn, their junior year was the year the simmering potential gelled into a big season that propelled them into the first round of the draft.

Barkley was arguably ahead of everyone in that group as a sophomore. We still only got glimpses of his ceiling (see the brilliant efforts against Stanford and Cal), but if USC is going keep its head above water throughout the depths of the sanctions era, it will have to be by Barkley continuing to shed the "potential" label and establishing himself as the best player on the field on a consistent basis. So far, the consistency hasn't been there. But he's still on schedule.